196 TEETIAET VEETEBRATA OP THE EATtyM. 



doubled, the posterior lobe still larger, and there are traces of a small postero-internal 

 tubercle. The dimensions (in centimetres) of the premolars are : — 



Length. Width. 



pm. 1 ,. . . .... 1'3 "7 



pm, 2 1'3 "8 



pm. 3 1'5 1 



pm. 4 1'6 1-2 



Length of premolar series 5-6. 



Geniohyus major, Andrews. 



[Text-fig. 63.J 



1904. Geniohyus major, C. W. Andrews, Greol. Mag. [5] vol. i. p. 212. 



Type Specimen. — Portion of left ramus of mandible with pm. 1-3 (text-fig. 63) ; 

 Geological Museum, Cairo. 



Text-fig. 63. 



Left lower premolars (pm. 1-pm. 3) of Geniohyus major. -J nat. size. 



This species is considerably larger than either of the others, the length of the three 

 premolars being 5'5 cm., while in G. minis the same teeth measure 3"6 cm. and in 

 G. fajumensis 4'1 cm. The posterior lobes of the premolars are still larger and more 

 selenodont than in G. fajumensis. 



Form. & hoc. — Fluvio-marine beds (Upper Eocene) : Birket-el-Qurun. 



C. 8980. Portion of left ramus of mandible with pm. 1-3 in good preservation. The teeth (text- 

 fig. 63) are very similar to those of G. fajmnensis, but the hinder lobe is wider and more 

 massive, and in wear gives an even more distinct V-shaped surface. The dimensions 

 (in centimetres) of the teeth are : — 



pm. 1 

 23m. 2 

 pm. 3 



M. 8876. Plaster cast of the above specimen. 



Made in the British Museum. 



